Cita APA (7a ed.)

Darwin, C., & Darwin, F. (1989). The expression of the emotions in man and animals. Pickering and Chatto.

Cita Chicago Style (17a ed.)

Darwin, Charles, y Francis Darwin. The Expression of the Emotions in Man and Animals. London: Pickering and Chatto, 1989.

Cita MLA (9a ed.)

Darwin, Charles, y Francis Darwin. The Expression of the Emotions in Man and Animals. Pickering and Chatto, 1989.